British star Benedict Cumberbatch tried to interview Julian Assange after signing up to play him on the big screen, but insists the WikiLeaks founder "was having none of it" and refused to meet him.

The actor plays the controversial whistleblower in upcoming movie The Fifth Estate, but admits he wasn't able to meet the man himself before stepping into his shoes for the role.

Cumberbatch tells Time Out magazine, "I didn't want to hang him out to dry (with my portrayal). I wanted to give a fair account of him. It's a living story, and the moral responsibility was very much part of the job. I tried to reach out to him, to communicate with him, and he was having none of it as far as a meeting goes.

"He felt that a meeting would condone a film he felt was too poisonous an account. He got hold of an old script and all sorts of issues blew up when we were filming. He tried to attack it and in his position I'd do the same, probably. We had a discussion, though, which was good. If Julian is feeling that way, politically he's right not to let that (a meeting) happen, because it would be like a blessing."

Assange has been living in Ecuador's embassy in London since June (12) as he battles extradition to Sweden, where he is wanted over allegations he sexually assaulted two women.